This SOW describes activities related to NCI?s Human Papillomavirus (HPV) vaccine evaluation efforts required for the next phase of these studies and will cover the follow-up of participants in both the existing trial of the bivalent HPV vaccine (Costa Rica Vaccine Trial or CVT) and the new trial aimed at evaluating the non-inferiority of 1 versus 2 doses of the HPV vaccines. Task A and Task B will run concurrently.